Of course measuring by volume for a given load, zero and sight settings is solely dependent on the manufacturer and the lot of powder you have from such.
Having Dropped hundreds if not into the thousands of charges from my Belding and Mull and weighing each and everyone, I can agree that for the most part a person comes up with those kinds of repeatable results. However once you start getting to the bottom of the hopper the weights start varying towards the light side and when you pour some fresh in it will weigh heavy. I try and keep the hopper filled over a 1/4 full when loading.
When switching between lots of powder from the same company, or between different manufacturers, you would be surprised at the difference in densities.
I have a case of Goex 2F that is less dense than the couple cans of Swiss 1.5 that I have, even though the granular size is equivalent.
I realize granular size has a big impact, but the case of Goex 1F that I have is much more dense than the aforementioned 2F and even though the 1F grains have more airspace, the same volume of it weighs more than the 2F I have. You would think the 2F should weigh more because of less airspace, but it doesn't.
Does it make a difference when hunting, probably not. Does it make a difference when shooting groups at 200 yards and beyond, definitely does. Different velocities will show up as vertical stringing. Different amounts of compression will show up as vertical stringing.
I have even gone as far as weighing my cases and measuring web thickness so that compression and internal volume in the cases is as close to the same as can be so that each and every shot is the same and that the problems in on the target are me, not the load.
When I do load development, I load 10 each of cartridges in increments of 1 grain of powder. After that, I will even go down to 1/2 grain changes to see if it will make a difference.
A 1 grain difference will turn a 5 or 6 in 200 yd group into a 2 - 2.5 in group. As I shoot out to 1000 yards, my standard (for as good as I can see and hold at the present time) is a 2.5 in group shot off cross sticks with a soule sight. For the most part I have found such a group size will hold accurate out to 1000 yards.
I have watched some of the muzzle loading slug gun shooters dropping charges with powder measurers. Of course they are not weighing the charges, but they are doing (or attempting to do) each and every motion the same as the last shot. Their ram rods are scribed so they compress the same, etc etc and it pays off on the targets for them. I have watched them shoot groups at 200 you can cover with a 1/2 dollar and sometimes with a quarter.
Last edited by drcook; October 11, 2012 at 10:21 AM.